In situ forming hydrogels based on polyethylene glycol itaconate for tissue engineering application

Abstract

Novel strategies have been proposed to enhance the quality of surgery by scheming noninvasive methods. For this reason, photo-curable in situ forming hydrogels have been well developed during advancements in the regenerative medicine. In this study, polyethylene glycol itaconate (PEGI) was synthesized by reacting polyethylene glycol (PEG) with different molecular weights (1000, 4000 and 8000 $$\hbox {g mol}^{-1}$$) and itaconyl chloride. The synthesized PEGIs were fully characterized and employed as a macromonomer for the preparation of in situ forming hydrogels using a combination of camphorquinone and dimethylaminoethyl methacrylate as a reactive photoinitiator system, and hydroxyethyl methacrylate as a reactive diluent. The physical properties of the hydrogels including gel yield, equilibrium swelling and compressive strength were determined. The hydrogel based on PEG 4000 with a gel yield of 86%, a water uptake of 103%, a compressive modulus of 11.2 MPa, an elongation at break of 9% and a curing time of 4 min was selected for the encapsulation of rabbit articular chondrocyte cells. The cytocompatibility of the in situ formed hydrogels was evaluated using 3[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide, live-dead fluorescence assays and optical microscopy observations. Glycosaminoglycans were quantified by dimethylmethylene blue staining from the encapsulated chondrocytes after 14 days. The proposed in situ forming hydrogel can be considered as an injectable and photocurable carrier for cell delivery in cartilage tissue engineering.